Valve closure for a piston compressor valve and method for operating the valve closure

ABSTRACT

A valve closure for a piston compressor valve including: a valve seat having a plurality of passage openings, a shaft having an axis of rotation (D), and a rotatable closing element connected to the shaft for opening and closing the passage openings, the valve seat having a flat end face, to which the passage openings lead and a center (Z): the passage openings extending radially to the center (Z); and the closing element having a center point (M) and a plurality of closing arms extending radially to the center point (M). The shaft can be rotated about the axis of rotation and can be slid in the extension direction of the axis of rotation extending perpendicularly to the end face and through the center (Z); each closing arm having a sealing surface substantially complementary to the passage openings in accordance with the rotation of the closing element.

The invention relates to a valve closure for a piston compressor valveas claimed in the preamble of claim 1. The invention furthermore relatesto a method for operating a valve closure as claimed in the preamble ofclaim 16.

PRIOR ART

Document WO 01/59266A1 discloses a valve for a piston compressor. Thisvalve comprises a valve seat and a rotatable closing element, whereinthe closing element, as a function of the rotary position thereof, opensor closes passage openings that are disposed in the valve seat. Thisknown valve has the disadvantages that relatively high wear arises, thatopening and closing of the valve takes a relatively long time, and thatthe sealing function of the valve is reduced over time by virtue of thearising wear.

SUMMARY OF THE INVENTION

It is an object of the invention to form a more advantageous valveclosure for a piston compressor valve.

This object is achieved by a valve closure comprising the features ofclaim 1. Dependent claims 2 to 15 relate to further advantageous designembodiments. The object is furthermore achieved by a method foroperating a valve closure, comprising the features of claim 16.Dependent claims 17 to 19 relate to further advantageous method steps.

The object is in particular achieved by a valve closure for a pistoncompressor valve, comprising a valve seat having a plurality of passageopenings, comprising a shaft having a rotation axis, and comprising aclosing element that for opening and closing the passage openings isrotatable about the rotation axis of the shaft, wherein the closingelement is fixedly connected to the shaft, wherein the valve seatcomprises a planar end side into which the passage openings open out,wherein the valve seat has a center, and wherein the passage openingsrun so as to be radial to the center, wherein the closing element has acenter point and a plurality of closing arms that run so as to be radialto the center point, wherein the shaft is mounted in the valve seat insuch a manner that the shaft is disposed so as to be rotatable about therotation axis as well as displaceable in the profile direction of therotation axis, wherein the rotation axis runs so as to be perpendicularto the end side and through the center, wherein each closing arm has asealing face that is aligned toward the end side, and wherein theclosing arms are configured so as to be substantially complementary tothe passage openings so as to as a function of the rotation of theclosing element close or open the passage openings by way of the sealingfaces.

The object is in particular also achieved by a valve closure for apiston compressor valve, comprising a valve seat having a plurality ofpassage openings, and comprising a closing element that for opening andclosing the passage openings is rotatable about a rotation axis, whereinthe valve seat comprises a planar end side into which the passageopenings open out, wherein the valve seat has a center, and wherein thepassage openings run so as to be radial to the center, wherein theclosing element has a center point and a plurality of closing arms thatrun so as to be radial to the center point, wherein the rotation axisruns so as to be perpendicular to the end side and through the center,wherein each closing arm has a sealing face that is aligned toward theend side, and wherein the closing arms are configured so as to besubstantially complementary to the passage openings so as to as afunction of the rotation of the closing element close or open thepassage openings by way of the sealing faces, wherein the closing armsare designed in such a manner that said closing arms have across-sectional face that decreases toward the periphery of said closingarms.

The object is furthermore particularly achieved by a method foroperating a valve closure of a piston compressor valve, wherein thevalve closure comprises a valve seat having a plurality of passageopenings, a shaft having a rotation axis, and a closing element that isfixedly connected to the shaft, wherein the shaft is mounted in thevalve seat so as to be rotatable about the rotation axis and so as to bedisplaceable in the direction of the rotation axis, wherein the closingelement for opening and closing the passage openings is rotated aboutthe rotation axis, wherein the closing element by virtue of a fluidpressure prevalent on the piston compressor valve is lifted in aself-acting manner in the direction of the rotation axis, and whereinthe closing element after lifting from the valve seat is rotated in amanner actively driven by the shaft and the passage openings are thuscompletely opened.

The object is furthermore particularly also achieved by a method foroperating a valve closure in that in a first method step the closingelement for opening the valve closure is lifted from the valve seat, andin that in a second method step the closing element after lifting isrotated to an open position.

The piston compressor valve according to the invention has the advantagethat the closing element thereof, in the case of a correspondingprevalent pressure differential, is lifted in a self-acting manner fromthe valve seat such that the closing element for completely opening thepassage openings is advantageously only activated, or rotated by meansactively acting thereon, respectively, when said closing element islifted from the valve seat. On account thereof, the closing element whenopening is not subjected to any or only very minor friction, thisresulting in less wear on the closing element and the valve seat, on theone hand, and on the other hand enabling the closing element to berotated by way of a minor force and in particular in a very rapid mannerso as to on account thereof completely open the piston compressor valve.Moreover, the piston compressor valve is advantageously completelyclosed in such a manner that the closing element in the lifted state inrelation to the valve seat is rotated from an open position to a closingposition in which the passage openings, when viewed in the profiledirection of the rotation axis, are completely covered by the closingelement, and the closing element subsequently, or simultaneously, or byway of a minor temporal offset, by the prevalent pressure differentialis moved in a self-acting manner toward the valve seat until the closingelement bears on the valve seat and completely covers the passageopenings such that the piston compressor valve is completely closedagain such that the closing of the piston compressor valve by theclosing element can also be performed very rapidly and without or withminor friction.

The closing element in the profile direction of the rotation axis isdisposed in the piston compressor valve so as to be smoothly movable insuch a manner that the closing element in the profile direction of therotation axis is moved or displaced, respectively, in a self-actingmanner by the pressure differential prevalent on the piston compressorvalve between the region of the inlet and the region of the outlet, orthe pressure differential prevalent on the closing element,respectively.

The piston compressor valve advantageously comprises a first rotationsub-axis, or a first sub-shaft, respectively, a second rotationsub-axis, or a second sub-shaft, respectively, and a coupling which isdisposed between the first and the second rotation sub-axis such thatthe first and the second rotation sub-axis by virtue of the coupling aremovable in a reciprocal manner, or displaceable in a reciprocal manner,respectively, in the profile direction of the rotation axis. Theactuator drive is preferably connected to the first rotation sub-axisand the closing element is fixedly connected to the second rotationsub-axis. The coupling in relation to a rotation about the rotation axisis particularly advantageously designed so as to be rotationally stablesuch that the closing element when rotating about the rotation axisfollows substantially or precisely rotation of the actuator drive. Thecoupling in the profile direction of the rotation axis is designed so asto be smoothly movable in such a manner that a pressure differentialprevalent on the closing element moves or displaces, respectively, thelatter in a self-acting manner in the profile direction of the rotationaxis. On account thereof, a movement of the closing element in theprofile direction of the rotation axis is guaranteed, on the one hand,and it is guaranteed, on the other hand, that the closing element by wayof the rotation axis is preferably rigidly connected to the actuatordrive which drives the rotation axis, this in turn enabling very rapidopening and closing of the closing element.

A plurality of variables are suitable as a state variable for detectingthe state of the piston compressor valve, in particular for detectingthe position of the closing element in relation to the valve seat, suchas, for example, a movement, for example the distance of the closingelement in the profile direction of the rotation axis, preferably thedistance between the closing element and the end side of the valve seat,or a direct mutual physical contact between the closing element and thevalve seat, for example, or an impact of the closing element or of therotation axis in the case of a completely lifted closing element, or thepressure differential on both sides of the piston compressor valveclosure, for example. An actuation device monitors the state variable,preferably compares the latter with a reference value, and opens orcloses, respectively, the closing element by correspondingly rotatingthe closing element, or by activating an actuator drive that rotates therotation axis, respectively, when a predefined condition is met. Thepiston compressor valve according to the invention is therefore capableof being switched in a precise, rapid, and repeatably identical manner.

The device according to the invention, or the method according to theinvention, respectively, has the advantage that the lifting of theclosing element from the valve seat is capable of being determined in anextremely precise manner, on the one hand because the closing element ismovable in a self-acting manner in the profile direction of the rotationaxis, and on the other hand because particularly preferably the movementof the closing element, or the distance between the closing element andthe valve seat is measured in the profile direction of the rotationaxis, respectively. The lifting of the closing element, or the point intime of lifting from the valve seat, respectively, can thus be preciselydetermined, and the actuator drive can subsequently be immediatelyactivated in order for the closing element to be rotated to the openposition. The closing element is preferably rotated from the closingposition to the open position within a duration of at least 2milliseconds to at most 10 milliseconds upon having been lifted from thevalve seat by the actuator drive. It is ensured on account of the rapidopening that the fluid flowing therethrough is imparted a minor flowresistance. When closing, the closing element by the actuator drive ispreferably rotated from the open position to the closing position withina duration of at least 2 milliseconds to at most 10 milliseconds, andthe closing element is simultaneously, or upon rotating having beenperformed, lowered in a self-acting manner toward the valve seat untilthe closing element bears on the valve seat.

In one advantageous design embodiment, the closing element is connectedto the actuator drive by way of a torsion spring, wherein part of thekinetic energy is stored in a torsion spring such that the closingelement is capable of being switched in a particularly rapid manner.

The valve closure of the piston compressor valve, comprising the valveseat and the closing element, is preferably designed in such a mannerthat the valve seat has a center and a plurality of passage openingswhich are disposed so as to be spaced apart in the circumferentialdirection and run radially toward the center, and that the closingelement has a plurality of radial arms and a rotation axis, wherein thearms run so as to be radial to the rotation axis, and wherein eachpassage opening is assigned one closing arm which is designed to be widein such a manner that said closing arm can completely cover the passageopening in a closed position, and in an open position cover said passageopening to an ideally minor extent or not at all. The closing arms aredesigned in such a manner that said closing arms have a cross-sectionalface that decreases toward the periphery, and on account thereof have amass reducing toward the periphery in that the closing arms are designedso as to be thinner toward the periphery, for example. A closing elementcomprising closing arms of this type toward the periphery has aparticularly minor mass and therefore has a reduced mass inertia, whichis why minor forces are required in order to activate the closingelement, that is to say to accelerate and decelerate, so as to switchthe closing element back and forth between a closing position and anopen position. The reduced mass inertia has the additional advantagethat lower forces are required for accelerating the closing element inthe profile direction of the rotation axis, or that the closing elementcan be moved more rapidly, or in a shorter time, respectively, in theprofile direction of the rotation axis. The closing element isparticularly preferably made from a plastics material and preferablycomprises a fiber reinforcement, preferably carbon fibers, so that theclosing element has a minor mass.

The closing element comprising a plurality of radial arms moreover hasthe advantage that the arms on the peripheries thereof are not mutuallyconnected to one another such that each closing arm can place itselfindividually onto the passage opening so that each closing arm canbetter correct any irregularities or traces of wear that are potentiallypresent on the passage opening or on the closing arm, in that eachclosing arm can bear individually on the valve seat. The cross-sectionalface that decreases toward the periphery preferably has the result thatthe closing arm moreover has a reduced flexural rigidity toward theperiphery, this resulting in the advantage that the closing arm canparticularly readily adapt to the profile of the valve seat when theclosing arm covers the passage opening, this resulting in particularlyadvantageous sealing.

In one advantageous design embodiment the valve closure for a pistoncompressor valve comprises a valve seat having a plurality of passageopenings, a shaft having a rotation axis, and a closing element that foropening and closing the passage openings is rotatable about the rotationaxis of the shaft, wherein the closing element is fixedly connected tothe shaft, wherein the valve seat comprises a planar end side into whichthe passage openings open out, wherein the valve seat has a center, andwherein the passage openings run so as to be radial to the center,wherein the closing element has a center point and a plurality ofclosing arms that run so as to be radial to the center point, whereinthe shaft is mounted in the valve seat in such a manner that the shaftis disposed so as to be rotatable about the rotation axis as well asdisplaceable in the profile direction of the rotation axis, wherein therotation axis runs so as to be perpendicular to the end side and throughthe center, wherein each closing arm has a sealing face that is alignedtoward the end side, and wherein the closing arms are configured so asto be substantially complementary to the passage openings so as to as afunction of the rotation of the closing element close or open thepassage openings by way of the sealing faces.

The shaft is preferably designed to be displaceable in the longitudinaldirection of the rotation axis in such a manner that the closing elementin the event of a corresponding prevalent pressure differential isdisplaceable in a self-acting manner in the longitudinal direction andis in particular capable of being lifted in a self-acting manner fromthe valve seat.

The closing arms are preferably designed in such a manner that saidclosing arms have a cross-sectional face that decreases towards theperiphery of said closing arms.

In the case of one advantageous method for operating a valve closure ofa piston compressor valve the valve closure comprises a valve seathaving a plurality of passage openings, a shaft having a rotation axis,and a closing element that is fixedly connected to the shaft, whereinthe shaft is mounted in the valve seat so as to be rotatable about therotation axis and so as to be displaceable in the direction of therotation axis, wherein the closing element for opening and closing thepassage openings is rotated about the rotation axis, wherein the closingelement by virtue of a fluid pressure prevalent on the piston compressorvalve is lifted in a self-acting manner in the direction of the rotationaxis, and wherein the closing element after lifting from the valve seatis rotated in a manner actively driven by the shaft and the passageopenings are thus completely opened.

In one advantageous method in a first method step the closing elementfor opening the valve closure is lifted from the valve seat, and in asecond method step the closing element after lifting is rotated to anopen position.

In one advantageous method the position of the closing element inrelation to the valve seat is measured, and the closing element isrotated about the rotation axis only upon having been lifted from thevalve seat.

In one advantageous method the closing element is rotated to the openposition within a duration of 2 milliseconds to 10 milliseconds uponhaving been lifted from the valve seat.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings used for explaining the exemplary embodiments:

FIG. 1 shows a longitudinal section through a valve with a drive, havinga closing element bearing thereon;

FIG. 2 shows a longitudinal section through the valve according to FIG.1, having a lifted closing element;

FIG. 3 shows a perspective view of a valve seat;

FIG. 4 shows a perspective view of a closing element which matches thevalve seat according to FIG. 3;

FIG. 5 shows a longitudinal section along the section line A-A throughthe closing element and the valve seat according to FIG. 6;

FIG. 6 shows a perspective view of the closing element and the valveseat having a lifted closing element;

FIG. 7 shows a perspective view of the arrangement according to FIG. 6,having the closing element in the open position;

FIG. 8 shows a longitudinal section through a pressure valve having alifted closing element;

FIG. 9 shows a longitudinal section through a further exemplaryembodiment of a suction valve, having a lifted closing element;

FIG. 10 shows a longitudinal section through a coupling device;

FIG. 11 shows a longitudinal section through a further exemplaryembodiment of a coupling;

FIG. 12 shows a longitudinal section through a bellows spring;

FIG. 13 shows a perspective view of a further exemplary embodiment of aclosing element;

FIG. 14 shows a perspective view of a further embodiment of a valveseat;

FIG. 15 shows a perspective view of the closing element associated withthe valve seat according to FIG. 14;

FIG. 16 shows a view of a detail of a section along the section line Bof the valve according to FIG. 14 in the closed state;

FIG. 17 shows the view according to FIG. 16 in the case of a liftedclosing element;

FIG. 18 shows the view according to FIG. 16 in the case of a liftedclosing element that is slightly rotated out of position;

FIG. 19 shows a perspective view of a further exemplary embodiment of avalve seat;

FIG. 20 shows a perspective view of a fragment of a further exemplaryembodiment of a closing element;

FIG. 21 shows a lateral view seen from the direction G-G of a radialclosing part according to FIG. 20;

FIG. 22 shows a section along the section line F-F through the closingpart according to FIG. 21;

FIG. 23 shows a section along the section line E-E through the closingpart according to FIG. 21;

FIG. 24 shows a lateral view seen from the direction G-G of a furtherexemplary embodiment of a radial closing part;

FIG. 25 shows a section along the section line H-H through the closingpart according to FIG. 24;

FIG. 26 shows a section along the section line I-I through the closingpart according to FIG. 24;

FIG. 27 shows a longitudinal section through a further exemplaryembodiment of a coupling device;

FIG. 28 shows a cross section along the section line C-C through thecoupling device according to FIG. 23;

FIG. 29 shows a view of a detail of an electromagnetic drive;

FIG. 30 shows the electromagnetic drive according to FIG. 29 having thearmature in a second basic position; and

FIG. 31 shows a further exemplary embodiment of the electromagneticdrive.

In principle, identical parts are provided with the same reference signsin the drawings.

PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows an actively controlled piston compressor valve 1 comprisinga valve seat 2 having a plurality of passage openings 2 a, comprising aclosing element 3 that for opening and closing the passage openings 2 ais rotatable about a rotation axis D, and comprising an actuator drive 5for rotating the closing element 3. The valve seat 2 has an end side 2 binto which the passage openings 2 a open out, wherein the closingelement 3 is connected to the actuator drive 5 so as to be movable inthe profile direction L of the rotation axis D such that the closingelement 3 is rotatable about the rotation axis D as well as displaceablein the profile direction L of the rotation axis D in relation to the endside 2 b. The shaft 4 is mounted in a bore 2 e of the value seat 2 or isan axial guide bearing, respectively. The valve 1 is disposed in a bellhousing 6 comprising passage openings 6 a and a cover 6 b. The closingelement 3 is illustrated in a lowered closed position such that theclosing element 3 bears on the end side 2 b of the valve seat 2 and thepassage openings 2 a are completely closed by the closing element 3. Thevalve 1 illustrated in FIG. 1 moreover comprises a sensor 8 fordetecting a state variable E of the closing element 3 or of the valve 1.The sensor 8 illustrated detects, for example, the movement of the shaft4 in the profile direction L, for example, the stroke path of the shaft4. An actuator device 20 detects the value measured by the sensor 8 andmoreover actuates the actuator drive 5. The closing element 3 is rotatedin the rotation direction of the rotation axis D, preferably from aclose position to an open position or vice versa, by actuating theactuator device 20. In one advantageous design embodiment, the actuatordevice 20 activates the actuator drive 5 as soon as the state variable Edeviates from a predefined nominal value. For example, the spacingbetween a sealing face 3 d of the closing element 3 and the end side 2 bof the valve seat 2, or a displacement path of the shaft 4 in theprofile direction L, or a pressure differential ΔP=P2−P1, that is to saythe difference between the pressure P2 on the one side of the closingelement 3 and the pressure P1 on the other side of the closing element3, is suitable as a state variable E. At least two sensors 8 arerequired for measuring the two pressures P1, P2. The shaft 4, in a waynot illustrated in detail, is connected to the drive 5 in such a mannerthat the shaft 4 in terms of rotation about the rotation axis D isdriven by the drive 5, on the one hand, and that the shaft 4 isdisplaceable in the longitudinal direction L in relation to the drive 5,on the other hand. The closing element 3 is particularly advantageouslydisplaced in a self-acting manner in the profile direction L in that thepressure differential prevalent on the closing element 3 results in theclosing element being displaced in the profile direction L and herein iseither lifted from the valve seat 2 or approaches the valve seat 2 andultimately bears on the end side 2 b of the valve seat 2. In thispreferred embodiment, the closing element 3 is mounted smoothly in sucha manner that the closing element by virtue of the prevailing pressuredifferential can displace itself in a self-acting manner in the profiledirection L. In a further potential design embodiment a drive (notillustrated) which at least partially facilitates the movement of theclosing element 3 in the profile direction L could also be provided.

FIG. 2 shows the valve according to FIG. 1 having a closing element 3 ina lifted open position in which the closing element 3 in relation to theend side 2 b is lifted in the longitudinal direction L. The closingelement 3 in the lifted open position by way of the actuator drive 5 ismoreover advantageously rotated about the rotation axis D in relation tothe closed position illustrated in FIG. 1 in such a manner that theclosing element 3 no longer covers the passage openings 2 a, asillustrated in FIG. 2 and FIG. 7, and the valve closure 1 a comprisingthe valve seat 2 and the closing element 3 is thus permeable to fluid inthe longitudinal direction L. By contrast to the sensor 8 illustrated inFIG. 1, the sensor 8 illustrated in FIG. 2 measures the distance fromthe end side 4 c of the shaft 4. The closing element 3 is fixedlyconnected to the rotation axis D, or to the shaft 4, respectively, suchthat the closing element 3 immediately follows a rotation about therotation axis D and that the rotation axis D, or the shaft 4,respectively, immediately follows a movement of the closing element 3 inthe longitudinal direction L.

FIG. 3 in a perspective view shows a first exemplary embodiment of avalve seat 2 having a central bore 2 e, or a center Z, respectively, andhaving a multiplicity of passage openings 2 a that run so as to beradially to the central bore 2 e, having webs 2 f running therebetween.The valve seat 2 moreover has an end side 2 b into which all passageopenings 2 a open out, wherein the end side 2 b in one advantageousdesign embodiment moreover also has an annular bearing face 2 c. Thevalve seat 2 illustrated has twenty-five passage opening 2 a which aredisposed so as to be uniformly distributed, or identically mutuallyspaced apart, respectively, in the circumferential direction, whereineach passage opening 2 a in one exemplary embodiment has a width of thecircumferential angle of 7°, and wherein each web 2 f has a width of thecircumferential angle of 7.4°. In order for the closing element to berotated from an open position to a closed position, or a closingposition, respectively, or vice versa, said closing element thus has tobe rotated by a rotation angle of 7.2°. The valve seat 2 advantageouslycomprises at least twenty passage openings 2 a which are disposed so asto be spaced apart in the circumferential direction and a correspondingidentical number of closing arms 3 a which for opening and closing thepassage openings 2 a are disposed in a reciprocal manner and spacedapart in the circumferential direction. This design embodiment of atleast twenty passage openings 2 a and radial arms 3 a has the sameadvantage in that the required maximum rotation angle of the closingelement is relatively small and in the case of this exemplary embodimentis 360° divided by 20 (number of passage openings) divided by 2 (halfthe angle having to be rotated) and is thus 9°.

FIG. 4 shows a perspective view of closing element 3 that matches thevalve seat 2 according to FIG. 3. The closing element 3 comprises a hub3 e having a central bore 3 c and comprises a multiplicity of closingarms 3 a which run so as to be radial to the central bore 3 c, or to arotation axis D, respectively, and which are mutually separated byintermediate spaces 3 b which extend up to the periphery 3 s. In oneexemplary embodiment, each intermediate space 3 b has a width of acircumferential angle of 7°, and each closing arm 3 a has a width of acircumferential angle of 7.4° such that the closing arms 3 a aredesigned so as to be slightly wider than the passage openings 2 a suchthat the passage openings 2 a in the case of a corresponding position ofthe closing element 3 are capable of being completely covered by theclosing arms 3 a. The closing element 3 is preferably designed so as tobe integral, or in one part, respectively, that is to say so as to becomposed of one part, and is advantageously made from a plasticsmaterial, for example from a fiber-reinforced plastics material, inparticular a carbon-fiber-reinforced plastics material (CFP). A CFP is acomposite material in which carbon fibers are embedded in a plasticsmaterial matrix, in most instances epoxy resin. The matrix materialserves for connecting the fibers as well as fulfilling the intermediatespaces. Other durable plastics or thermosetting plastics are alsosuitable as a matrix material. However, the closing element can also bemade from a plastics material without the addition of fibers.

FIGS. 6 and 7 show the actual valve closure 1 a comprising the closingelement 3 as well as the valve seat 2 in two potential reciprocalpositions. FIG. 5 moreover shows a section through the closing element 3and through the valve seat 2 as indicated along the section line A-Aillustrated in FIG. 6. The valve closure 1 a, that is to say the closingelement 3 and the valve seat 2, can assume substantially four differentreciprocal positions, specifically a lowered closed position, a liftedclosed position, a lifted open position, and a lowered open position.Lifted means that the closing element 3 is lifted in relation to thevalve seat 2 and thus is spaced apart therefrom, as is illustrated inFIGS. 2 and 5 to 7. Lowered means that the closing element 3 bears onthe valve seat 2, as is illustrated in FIG. 1. The valve 1, or the valveclosure 1 a, respectively, is completely closed only in the loweredclosed position illustrated in FIG. 1, in that the closing element 3bears on the valve seat 2 and the passage openings 2 a are completelyclosed by the closing element 3 bearing thereon, or the closing arms 3 aof said closing element 3, respectively. In the case of the liftedclosed position illustrated in FIGS. 5 and 6, the closing element 3 isspaced apart from the valve seat 2, wherein the closing element 3, orthe closing arms 3 a thereof, respectively, cover the passage openings 2a in a spaced-apart manner such that only a small gap S through whichfluid flowing in or out could flow exists between the closing element 3and the valve seat 2. In the case of the lifted open positionillustrated in FIG. 7, the closing element 3 is spaced apart from thevalve seat 2, wherein the closing element 3 has been rotated in therotation direction D1 in comparison to the position according to FIG. 6such that the passage openings 2 a in the longitudinal direction L, orin the profile direction of the rotation axis D, respectively, are nolonger covered by the closing element 3, or the closing arms 3 athereof, respectively, or if at all overlap to a minimum extent on therim such that a largest possible area of the passage openings 2 a in thelongitudinal direction L is open to fluid flowing therethrough and thefluid flowing through the completely open valve closure 1 a is notimpeded by the closing element 3, or the radially running closing arms 3a thereof, respectively, or is impeded only to a negligible extent.Should the closing element 3 illustrated in FIG. 7 be lowered such thatsaid closing element 3 would bear on the valve seat 2, the closingelement 3 would thus assume a lowered open position in which the passageopenings 2 a are open to the maximum, preferably completely open, but atleast open to the maximum, wherein the maximum opening area isdetermined by the width in the circumferential direction of a respectiveclosing arm 3 a and the width in the circumferential direction of arespective passage opening 2 a. The closing element 3 is opened and thusmoved to an open position by the actuator drive 5 by way of a rotationin the rotation direction D1, and is closed and thus moved to a closingposition by a rotation in the rotation direction D2. Moreover, by virtueof the forces engaging on the closing element 3, in particular thepressure differential of the fluid, the closing element 3 moves in aself-acting manner in the longitudinal direction L such that the closingelement 3 is in this direction lifted or lowered in relation to thevalve seat 2. As is illustrated in FIG. 6, the rotation axis D runsthrough the center point M of the closing element 3, or through thecenter Z of the valve seat 2, respectively. FIG. 7 moreover shows thatthe closing element 3 has a fastening side 3 g in which fastening bores3 h which serve for fastening the closing element 3 to the shaft 4 aredisposed.

FIG. 5 shows a section along the section line A-A according to FIG. 6.The closing element 3 is lifted in relation to the valve seat 2. Theclosing element 3 comprises a hub 3 e having a center point M, whereinthe hub 3 e comprises a central bore 3 c, a planar friction face 3 f,and a fastening side 3 g. The closing arms 3 a taper off toward theoutside in the radial direction and therefore have a cross-sectionalface that decreases toward the periphery 3 s. The tapering results inthe advantage that the mass of the closing arms 3 a is reduced towardthe outside, which reduces the weight and the mass inertia of theclosing element 3. The height 3 t of the closing arms 3 a is reducedtoward the periphery 3 s in the exemplary embodiment according to FIG.5. The closing arm 3 a has a consistent height 3 t in thecircumferential direction D; this means that the closing arm 3 a acrossthe entire width thereof has the same height 3 t.

In one exemplary method, the piston compressor valve 1 illustrated inFIGS. 1 and 2 can be operated in such a manner that a state variable Eof the closing element 3, for example the displacement path S1 of theshaft 4 in the longitudinal direction L, is measured, wherein theclosing element 3, as is illustrated in FIG. 1, is initially disposed inthe lowered closed position, wherein the shaft 4 is movable in aself-acting manner in the longitudinal direction L, and wherein theclosing element 3 as a function of the pressure of an operating gasacting on the valve 1 or on the closing element 3, respectively, can belifted from the valve seat 2. The state variable E is detected and thedrive 5 is activated as soon as the state variable E exceeds apredefined nominal value such that the closing element 3 by way of thedrive 5 is rotated to the lifted open position illustrated in FIG. 2 bya rotation about the rotation axis D, wherein the rotating takes placeby way of the drive 5, and the lifting in the longitudinal direction Ltakes place in a self-acting manner. A travel signal of the sensor 8 isused as the state variable E, for example, in that the displacement ofthe shaft 4 in the direction of the longitudinal axis L is measured,wherein said displacement preferably corresponds to the spacing betweenthe closing element 3 and the end side 2 b. As soon as the statevariable E exceeds a predefined nominal value, for example 0.1 mm, thedrive 5 is activated and the closing element 3 rotated to the openposition illustrated in FIG. 2 or FIG. 7.

FIG. 8 shows a valve 1 designed as a pressure valve, wherein the closingelement 3 is situated in a lifted closed position. The closing element 3is disposed between the valve seat 2 and the drive 5. By contrastthereto, the valve seat 2 in FIG. 2 is disposed between the closingelement 3 and the drive 5. The valve according to FIG. 8 comprises afirst shaft part 4 a, or a first rotation sub-axis, respectively, and asecond shaft part 4 b, or a second rotation sub-axis, respectively,which are connected to one another by way of coupling 9. The first shaftpart 4 a is immovable in the longitudinal direction L, whereas thecoupling 9 permits a movement in the longitudinal direction L such thatthe second shaft part 4 b is movable in the longitudinal direction L. Inthe exemplary embodiment according to FIG. 8, the bore 2 e, or the axialguide bearing, respectively, is designed as a pocket hole in which thesecond shaft part 4 b is guided in a radial and axial manner. Otherwise,the components including valve seat 2, closing element 3, drive 5, andbell housing 6 have already been described in the context of FIGS. 1 and2. In one further embodiment, the second shaft part 4 b could bedispensed with in that the closing element 3 is connected directly tothe coupling 9. The coupling 9 is preferably designed so as to beelastic or resilient in the longitudinal direction L in such a mannerthat the closing elements 3 by virtue of the engaging flow forces canmove in a self-acting manner in the longitudinal direction L.

FIG. 9 shows a further valve 1 designed as a suction valve. By contrastto the valve 1 according to FIG. 2, the valve 1 according to FIG. 9 hasa torsion spring 7 which comprises an inner torsion spring 7 a as wellas an outer hollow torsion bar 7 b. The inner torsion spring 7 a at theone end thereof is connected to the drive 5, and at the other endthereof is connected to a hollow torsion bar end 7 d of the outer hollowtorsion bar 7 b. The hollow torsion bar 7 b at one end is connected tothe cover 6 b by way of a fastening 7 c, and at the other end isconnected to the hollow bar end 7 d. The hollow bar end 7 d is connectedto a hollow-cylindrical connection part 10 in which a sensor 8 isdisposed. The connection part 10 is connected to the shaft 4 by way ofthe coupling 9. The coupling 9 is designed in such a manner that thecoupling can vary the length thereof in the longitudinal direction L.The coupling is preferably designed so as to be elastic, preferablyspring-elastic, in the longitudinal direction L. The shaft 4 on accountof the coupling 9 is thus disposed so as to be movable in relation tothe connection part 10, or the torsion spring 7, respectively, in thelongitudinal direction L, or so as to be displaceable in thelongitudinal direction L, respectively. The torsion spring 7 is designedso as to be immovable in the longitudinal direction L. The drive 5causes a rotation of the inner torsion spring 7 a out of position, andby way of the hollow bar end 7 d moreover causes a rotation of the outerhollow torsion bar 7 b out of position. Moreover, the connection part 10and the coupling 9 and, on account thereof, the shaft 4 are rotated byrotating the hollow bar end 7 d. The coupling 9 is configured in such amanner that said coupling 9 in the longitudinal direction L permits achange in length and preferably has a spring effect, and in particularelastic properties. The coupling 9 in terms of a rotation about therotation axis D preferably has ideally rigid properties such that theclosing element 3 and the shaft 4 by way of the coupling 9 are connectedin a rotationally fixed manner to the connection part 10 and the hollowbar end 7 d. The publication WO 2009/050215 A2 discloses a potentialmethod for operating the valve in detail. The content of saidpublication is hereby incorporated in the present patent application.

FIG. 10 shows a longitudinal section through a further exemplaryembodiment of a connection between the torsion spring 7 and the shaft 4,wherein the connection is composed of the coupling part 9 which ismovable, and in particular spring-elastic, in the longitudinal directionL. The coupling part 9 in terms of a rotation about the rotation axis Dis designed so as to be preferably ideally rigid, preferably stableagainst rotating out of position. The coupling part 9 illustrated inFIG. 10 is designed as a bellows spring. The bellows spring 9 ispreferably composed of metal so as to achieve a high torsional rigiditywhen rotating about the rotation axis D. The bellows spring 9 isdesigned in such a manner that said bellows spring 9 has elasticproperties in the longitudinal direction L, wherein the elasticproperties are capable of being determined, for example, by the warthickness of the bellows spring, the chosen material, preferably metal,as well as the geometric structure of the bellows spring. In oneadvantageous design embodiment, a sensor 8 is disposed in the interiorspace 9 g which sensor 8 measures a distance in the longitudinaldirection L, for example the distance from an end side 9 f of thebellows spring 9 that is disposed opposite thereto. In one particularlyadvantageous design embodiment, the coupling part 9 configures aninterior space 9 g that is closed off in a gas-tight manner in relationto the exterior such that no contamination emanating from the outsidecan be deposited in the interior space 9 g, so that the sensor 8 canmeasure the distance from the end side 9 f in a long-term reliable andlow-maintenance manner. The coupling 9 illustrated in FIG. 11 can alsobe used, for example, in a valve 1 as is illustrated in FIG. 1, 2, or 8,in that the continuous shaft 4 is subdivided into a first shaft part 4 aand a second shaft part 4 b and said two shaft parts 4 a, 4 b areconnected to a coupling 9 as is described by way of FIG. 10 so that theshaft 4 illustrated in FIG. 1, 2, or 8 by virtue of the coupling 9 thatis disposed on the shaft 4 has a resilient properties in thelongitudinal direction L.

FIG. 11 shows a longitudinal section through a further exemplaryembodiment of a connection between the torsion spring 7 and the shaft 4wherein the connection comprises a combination of a hollow-cylindricalconnection part 10 and a coupling part 9, wherein the coupling part 9 isdesigned as a bellows spring as is described in FIG. 10 or 12. In oneadvantageous design embodiment a sensor 8 is disposed in the connectionpart 10 which sensor 8 measures the distance from an end side 9 f of thebellows spring 9 that is disposed opposite thereto, for example. In oneparticularly advantageous design embodiment the connection part 10 aswell is the coupling part 9 designed as the bellows spring 9 configure acommon interior space 9 g that is closed off in a gas-tight manner inrelation to the exterior. The arrangement illustrated in FIG. 11,comprising the connection part 10 as well as the bellows spring 9, canalso be used, for example, in a valve 1 as is illustrated in FIG. 1, 2,or 8. An eddy current sensor is suitable as the sensor 8, for example.

FIG. 12 shows a further exemplary embodiment of a coupling 9, comprisinga bellows-shaped, preferably metallic, external casing 9 i havingbellows-shaped convexities 9 k and an interior space 9 g which ispartially filled with an elastic filler material (illustrated in hatchedlines) such that an open, cylindrical internal cavity 9 h still remains,for example. The elastic filler material serves for determining thespring rate, or the spring elastic, respectively, of the coupling 9 inthe longitudinal direction L, wherein said spring rate is determined inparticular by the elasticity of the filler material and/or the disposalof the filler material in the bellows-shaped convexities 9 k of theexternal casing 9 i. The elastic filler material is preferably composedof an elastic plastics material. The elastic filler material is disposedin the internal cavity 9 h, wherein at least some of the bellows-shapedconvexities 9 k, and preferably all convexities 9 k, as illustrated, arepreferably completely filled with the elastic filler material 9 g. Inorder for the closing element 3 to be moved in a reliable andself-acting manner in the longitudinal direction L, the couplingrequires a spring rate which is correspondingly adapted to the forcesthat in the longitudinal direction L engage on the closing element 3.The coupling parts 9 illustrated in FIGS. 10 to 12 can be produced in amultiplicity of different spring rates, depending on the requirement.

FIG. 13 shows a perspective plan view of a further exemplary embodimentof a closing element 3. The lower side of the closing element 3 could bedesigned as is illustrated in FIG. 4. The closing element 3 comprises ahub 3 e having a central bore 3 c, a center point M, and a plurality ofclosing parts 3 a that run so as to be radial to the center point M andare mutually spaced apart in the circumferential direction. Each radialarm 3 a is composed of a plate-shaped part 3 w and a rib 3 i that isfixedly connected thereto, wherein each plate-shaped part 3 w in theradial direction extends up to the periphery 3 s. Each rib 3 i on theside that faces away from the passage opening 2 a projects beyond theplate-shaped part 3 w in the direction of the rotation axis D. The rib 3i has a height 3 t that decreases toward the periphery 3 s and, onaccount thereof, a decreasing cross-sectional face. The flexuralrigidity of the closing parts 3 a depends in particular on the designembodiment of the projecting rib 3 i. The height 3 t of the rib 3 i isadvantageously reduced in the radial direction toward the outside so asto reduce the mass of the rib 3 i toward the outside and so as to inparticular reduce the mass of the closing element 3 in a radiallyoutward manner so as to on account thereof reduce the mass inertia ofthe closing element 3 in particular in relation to a rotating movementabout the rotation axis D.

FIG. 14 shows a perspective plan view of a valve seat 2 which bycontrast to the embodiment illustrated in FIG. 3 has support elements 2d which on the annular face 2 c protrude in the direction of therotation axis D and in the circumferential direction are mutually spacedapart, preferably uniformly mutually spaced apart, and which run so asto be radial in relation to the bore 2 e. FIG. 15 shows a perspectiveview of a closing element 3 which by contrast to the embodimentillustrated in FIG. 4 in the surface of the hub 3 e has depressions 3 kwhich run so as to be radial to the central bore 3 c and are disposed ina reciprocal manner to the support elements 2 d. The valve seat 2according to FIG. 14 and the closing element 3 according to FIG. 15 aredesigned so as to be mutually adapted in such a manner that the samenumber of projecting support elements 2 d and depressions 3 k aredisposed in such a manner that one opposite depression 3 k is providedfor each support element 2 d and the respective support element 2 d canengage in the opposite depression 3 k. FIGS. 16 to 18 in a section alongthe section line B according to FIG. 14 show the valve seat 2 and theclosing element 3 in various positions. In FIG. 16, the closing element3 has a lowered closed position, wherein the closing element 3 bears onthe valve seat 2, and wherein each support element 2 d engages in thedepression 3 k disposed opposite thereto, wherein the projecting supportelement 2 d is completely accommodated in the depression 3 k such thatthe bearing face 2 c bears in a planar manner on the hub 3 e. In thecase of FIG. 17, an upwardly directed positive pressure differential ΔPis prevalent on the closing element 3 which results in that the closingelement 3 in relation to FIG. 16 is lifted in the longitudinal directionL such that the closing element 3 is situated in a lifted closedposition in which the closing element 3 is lifted but has not yet beenrotated out of position about the rotation axis D in relation to theposition according to FIG. 16. As soon as the closing element 3 issituated in the position illustrated in FIG. 17, the closing element 3can be rotated about the rotation axis D. FIG. 18 shows the closingelement 3 in a lifted position in which the closing element 3 inrelation to FIG. 16 is lifted in the longitudinal direction L, and theclosing element 3 is rotated out of position in the rotation directionof the rotation axis D. FIG. 18 shows a situation in which a downwardlydirected negative pressure differential ΔP is prevalent on the closingelement 3 which results in that the closing element 3 is urged to belowered in the direction of the valve seat 2, this however beingprevented by the support element 2 d on which the closing element 3bears. The end face of the support element 2 d that bears on the closingelement 3 is comparatively small, this resulting in the advantage thatthe rotation force which is required for rotating the closing element 3in the rotation direction D2 of the rotation axis D is relatively small.The support element 2 d thus has the advantage that the resistance torotation between the closing element 3 and the valve seat 2 is reducedin comparison to an embodiment without a support element 2 d, so thatthe closing element 3 can still be reliably rotated even when, asillustrated, a negative pressure differential ΔP is prevalent on theclosing element 3, said pressure differential ΔP urging the closingelement 3 against the valve seat 2. The valve 1 according to theinvention can therefore be reliably operated in a larger range ofprevailing pressure differentials. The support element 2 d has thefurther advantage that the wear on the closing element 3 and the valveseat 2 is moreover reduced in the case of a negative pressuredifferential ΔP should said closing element 3 and said valve seat 2 bemutually rotated out of position in the case of a negative pressuredifferential ΔP.

In a further exemplary embodiment, depressions instead of supportelements 2 d can be disposed on the valve seat 2, and in a reciprocalmanner support elements instead of depressions 3 k could be disposed inthe closing element 3.

FIG. 19 shows a further exemplary embodiment of a valve seat 2 which bycontrast to the embodiment illustrated in FIG. 3 has a plurality ofrolling members 12 that are spaced apart in the circumferentialdirection in the annular phase 2 c. Said rolling members 12 projectslightly beyond the annular face 2 c, for example by 1/10 mm. Therolling members 12 serve for reducing the sliding resistance or rollingresistance, respectively, of the rotating closing element 3 that bearson the valve seat 2, or on the annular bearing face 2 c, respectively.The rolling members 12 are preferably designed so as to be cylindricalor conical and are preferably composed of metal or ceramics.

FIG. 20 in fragments shows a further exemplary embodiment of a closingelement 3, comprising a hub 3 e having a central bore 3 c, andcomprising a plurality of radial closing parts 3 a that are disposed soas to be mutually spaced apart in the circumferential direction and areconnected to the hub 3 e. FIG. 21 shows a lateral view of a singleclosing part 3 a according to FIG. 20, seen from the direction G. FIG.22 shows a longitudinal section F-F of the closing part 3 a, and FIG. 23shows a cross section of the closing part 3 a along the section lineE-E. The closing part 3 a comprises a first and a second radial lateralwall 3 m, 3 n, and a cover phase 3 r, which limit an interior space 3 o.The first and the second radial lateral wall 3 m, 3 n run in such amanner that said lateral walls 3 m, 3 n moreover configure in each caseone planar sealing face 3 d which is aligned toward the valve seat 2, asis illustrated in FIG. 23. Said two sealing faces 3 d, conjointly withthe sealing face 3 d that is disposed on the hub 3 e and the sealingface 3 d that is disposed in the region of the periphery 3 s of theclosing part 3 a, can bear on the end side 2 b of a valve seat 2, as isillustrated in FIG. 22, and sealed the passage openings 2 a, for examplein the case of the valve seat 2 according to FIG. 3, in that thementioned sealing faces 3 d bear on the end side 2 b. The closingelement 3 in the lowered closed position bears on the valve seat 2,wherein the closing element 3 in relation to the valve seat 2 isdisposed in such a manner that the sealing faces 3 d bear on the endside 2 b and enclose the passage opening 2 a, wherein the spoon-shapedinterior space 3 o of the closing part 3 a herein lies above the passageopening 2 a, being fluidically connected thereto. The closing element 3illustrated in FIGS. 20 to 23 has the advantage that the radial closingparts 3 a, in particular by virtue of the lateral walls 3 m, 3 n, in thecase of a corresponding choice of material have a high rigidity and thatthe radial closing parts 3 a can on the other hand be designed so as tobe light in mass, which in the case of a rotation of the closing element3 about the rotation axis D results in the advantage that said closingelement 3 has a reduced inert mass. On account thereof, a lower effortin terms of force is required for rotating the closing element 3 aboutthe rotation axis D, more specifically during the acceleration phase andduring the deceleration phase, for moving the closing element 3 from anopen position to a closed position and vice versa from a close positionto an open position.

FIG. 24 shows a lateral view of a further exemplary embodiment of asingle closing part 3 a, again seen from the direction G. FIG. 25 showsa longitudinal section of the closing part 3 a according to FIG. 24along the section line H-H, and FIG. 26 shows a cross section of theclosing part 3 a along the section line I-I. The closing part 3 a againcomprises a first and a second radial lateral wall 3 m, 3 n, and a coverface 3 r, wherein the radial lateral walls 3 m, 3 n by contrast to theexemplary embodiment according to FIGS. 21 to 23 are designed so as tobe wider and project beyond the cover phase 3 r, as is illustrated inFIGS. 24 to 26. Said lateral walls 3 m, 3 n that are wider in theprofile direction of the rotation axis D result in the advantage thatthe radial closing part 3 a in the case of an identical wall thicknessof the lateral walls 3 m, 3 n has either a high stability or a higherflexural rigidity, respectively, or that the lateral walls 3 m, 3 n aredesigned so as to be thinner, and the closing part 3 a thus has a lowermass. All closing parts 3 a of one closing element 3 are advantageouslydesigned in an identical manner.

FIG. 27 shows a longitudinal section through a further exemplaryembodiment of the coupling 9 which is an alternative to the coupling 9according to FIGS. 10 and 11. FIG. 28 shows a section of the couplingaccording to FIG. 27 along the section line C-C. As has already beendescribed in the context of FIGS. 10 and 11, the coupling 9 illustratedin FIGS. 27 and 28 also has a mobility in the longitudinal direction L,whereas the coupling 9 is rigid against rotation out of position inrelation to a rotation about the rotation axis D. The coupling 9comprises a first coupling part 9 a which is fixedly connected to thefirst shaft part 4 a, and comprises a second coupling part 9 b which isfixedly connected to the second shaft part 4 b. The first coupling part9 a comprises an angular recess 9 d, and the second coupling part 9 bcomprises an angular appendage 9 c, wherein the recess 9 d and theappendage 9 c are designed so as to be mutually adapted in such a mannerthat a reciprocal movement in the longitudinal direction L is possible,wherein a reciprocal rotation out of position about the rotation axis Dis barely or not at all possible. The first and the second coupling part9 a, 9 b are connected to one another in a spring-elastic manner by wayof an elastic spring part 9 e such that the first and the secondcoupling part 9 a, 9 b can carry out a reciprocal movement in thelongitudinal direction L. The spring part 9 e can be designed so as tobe hollow-cylindrical, as illustrated, and be composed of a plasticsmaterial, for example. In one advantageous design embodiment, a sensor 8which measures the distance, or the variation in distance, respectively,between the two coupling parts 9 a, 9 b in that the distance between thesensor 8 and the end side 9 f is measured, for example, is disposed asillustrated within the coupling 9. In one advantageous designembodiment, the coupling 9 has a detent 9 l which delimits the maximumstroke path of the coupling 9. The elasticity of the spring part 9 e ispreferably chosen in such a manner that the closing element 3 can movein a self-acting manner in the longitudinal direction L.

FIG. 29 shows an electromagnetic drive 5 in a first basic position, andFIG. 30 shows the same electromagnetic drive 5 in a second basicposition. The drive 5 comprises a stator 5 a having four yokes 5 b andinterior spaces 5 c for coils. The electrically conducting coils forgenerating the magnetic field that are wound about each of the fouryokes 5 b and run in the interior space 5 c are not illustrated. Thedrive 5 moreover comprises an armature 5 d which is preferably fixedlyconnected to the shaft 4 or to the torsion spring 7 and which is mountedso as to be pivotable about the rotation axis D. The drive 5 is designedin such a manner that the maximum pivoting range of the armature 5 d isslightly larger than the angle required for rotating the closing element3. Depending on the design embodiment in terms of construction, thedrive 5 preferably has a pivot angle in a range from 5° to 20°. Rotatingthe closing element 3 from the open position to the closed position by7.2° means that the open position conjointly with the close position inthe circumferential direction in total occupy a rotation angle of intotal 14.4° such that the valve seat 2 has twenty-five passage openings2 a that in the circumferential direction are uniformly mutually spacedapart, as is illustrated in FIG. 3. Accordingly, the armature 5 d of thedrive 5 would have to pivot about a slightly larger angle, for exampleabout an angle in the range from 8° to 10°, in particular depending onthe rigidity of the first shaft part 4 a against rotation out ofposition. The valve seat 2 illustrated in FIG. 3 has the advantage thata small rotation angle is required from the open position to the closedposition, this enabling particularly rapid switching, or a particularlyshort switching time, respectively. The drive 5 illustrated in FIGS. 29to 31 is suitable for rotating the closing element 5 as is shown inFIGS. 1, 2, 8, and 9, about an angular range of, for example, 7.2°, soas to drive the closing element 5 and rotate the latter from the openposition to the close position, or vice versa.

In one particularly advantageous design embodiment, as is illustrated inFIG. 31, damper elements 5 f are disposed on the end portions of thearmature 5 d, the task of said damper elements 5 f being to preventdirect contact between the armature 5 d and the yoke 5 b. The damperelements 5 f are composed of a non-magnetic material, for examplealuminum, or a plastics material. This design embodiment has anadvantage that sticking of the armature 5 d on the yoke 5 b is preventedsuch that it is ensured that the armature 5 b is immediately releasedfrom the yoke 5 b when a corresponding magnetic field for switching thearmature 5 d is applied to the drive 5. The piston compressor valve 1illustrated in FIGS. 1, 2, 8, 9, comprising a drive 5 is illustrated inFIGS. 29 to 31, can be very rapidly switched from a closed position toan open position and vice versa, wherein the switching time is less than0.1 second, and particularly advantageously lies in the range ofapproximately 2.5 milliseconds, or lies in the range between 2 to 10milliseconds.

It is not necessary for the rotation angle of the closing element 3 tobe detected as a state variable E of the closing element 3, since noindication pertaining to the displacement of the closing element 3 inthe longitudinal direction L can be derived from said state variable,and thus based on said state variable no decision can be made as to thepoint in time at which the actuator drive 5 is to be activated. However,with a view to the reliable operation of the piston compressor valve itcan prove advantageous for the rotation angle of the closing element 3,or a variable associated therewith, in particular the rotation angle ofthe actuator drive 5, to also be additionally measured. Moreover, it isadvantageous for the crankshaft angle of the compressor to be measured.By way of the crankshaft angle of the compressor it can be determinedwhen, or at which crankshaft angle, respectively, the piston compressorvalve has to be opened or closed, respectively, or at which crankshaftangle the exhaustion of gas, or the induction of gas, respectively, ofthe piston compressor valve takes place. Malfunctions of the closingelement 3 can be detected by measuring the rotation angle of the closingelement 3, for example, and error signals can be generated, or thepiston compressor can be stopped in an emergency, for example, shouldthe closing elements 3 not be opened and closed by the rotation of theclosing element 3 in a cycle predefined by the crankshaft angle.

1. A valve closure for a piston compressor valve, comprising a valveseat having a plurality of passage openings, comprising a shaft having arotation axis (D), and comprising a closing element that for opening andclosing the passage openings is rotatable about the rotation axis (D) ofthe shaft, wherein the valve seat comprises a planar end side into whichthe passage openings open out, wherein the valve seat has a center (Z),and wherein the passage openings run so as to be radial to the center(Z), wherein the rotation axis (D) runs so as to be perpendicular to theend side and through the center (Z), wherein the closing element isdesigned in one piece, that the closing element is fixedly connected tothe shaft, that the closing element has a center point (M) and aplurality of closing arms that run so as to be radial to the centerpoint (M), that the shaft is mounted in the valve seat in such a mannerthat the shaft is disposed so as to be rotatable about the rotation axis(D) as well as displaceable in the profile direction (L) of the rotationaxis (D), that each closing arm has a sealing face that is alignedtoward the end side, and that the closing arms are configured so as tobe substantially complementary to the passage openings so as to as afunction of the rotation of the closing element close or open thepassage openings by way of the sealing faces.
 2. The valve closure asclaimed in claim 1, wherein the shaft is designed to be displaceable inthe longitudinal direction (L) of the rotation axis (D) in such a mannerthat the closing element in the event of a corresponding prevalentpressure differential is displaceable in a self-acting manner in thelongitudinal direction (L) and is in particular capable of being liftedin a self-acting manner from the valve seat.
 3. The valve closure asclaimed in claim 1, wherein the closing arms are designed in such amanner that said closing arms have a cross-sectional face that decreasestoward the periphery of said closing arms.
 4. The valve closure asclaimed in claim 1, wherein the closing element comprises a hub which isdisposed so as to be symmetrical to the rotation axis (D), and in thatthe closing arms, proceeding from the hub, run in the radial direction,and in that the end side of the valve seat in the radial direction interms of the center (Z) in a first sub-portion has an annular bearingface and, following thereon in the radial direction, in a secondsub-portion has the passage openings.
 5. The valve closure as claimed inclaim 1, wherein at least twenty passage openings are disposed so as tobe mutually spaced apart uniformly in the circumferential direction tothe rotation axis (D), and in that the same number of closing arms aredisposed so as to be mutually spaced apart uniformly in thecircumferential direction to the rotation axis (D).
 6. The valve closureas claimed in claim 3, wherein the closing arms in the profile directionof the rotation axis (D) have a height, and in that the height of theclosing arms decreases toward the periphery.
 7. The valve closure asclaimed in claim 3, wherein each closing arm in the circumferentialdirection to the rotation axis (D) has a consistent height.
 8. The valveclosure as claimed in claim 1, wherein each closing arm is composed of aplate-shaped part and a rib that is fixedly connected thereto, in thateach plate-shaped part in the radial direction extends up to theperiphery, in that each rib on the side that faces away from the passageopening projects beyond the plate-shaped part in the direction of therotation axis (D), and in that the rib has a height that decreasestoward the periphery.
 9. The valve closure as claimed in claim 1,wherein each closing arm comprises a first radial lateral wall (3 m) anda second radial lateral wall that is spaced apart in the circumferentialdirection, in that the sides of the first and of the second lateral wallthat is aligned toward the end side form part of the sealing face of theclosing arm, in that the height of the first and of the second radiallateral wall (3 m, 3 n) decreases toward the periphery, in that a coverface that runs in the circumferential direction connects the firstradial lateral wall (3 m) to the second radial lateral wall in afluid-tight manner, wherein the cover face is disposed so as to bespaced apart from the sealing face in the direction of the rotation axis(D) such that the closing arm has an internal cavity which toward theend side is delimited by an encircling sealing face.
 10. The valveclosure as claimed in claim 9, wherein the first and the second lateralwall project beyond the cover face in the direction of the rotation axis(D).
 11. The valve closure as claimed in claim 1, wherein the closingarm toward the periphery thereof has a decreasing flexural rigidity. 12.The valve closure as claimed in claim 4, wherein the hub toward the endside has a planar friction face which runs so as to be concentric withthe rotation axis (D) and is designed so as to be adapted to the annularbearing face such that the planar friction face can slide on the annularbearing face.
 13. The valve closure as claimed in claim 4, wherein theannular bearing face has support elements that project in the directionof the rotation axis (D), and the friction face has depressions that aredisposed in a reciprocal manner to the support elements, or in that thefriction face has support elements that project in the direction of therotation axis (D), and the annular bearing face has depressions that aredisposed in a reciprocal manner to the support elements, wherein thedepressions are disposed in such a manner that the support elements liein the depression only in a rotary position of the closing element inwhich the passage openings are substantially closed, and in that thesupport elements and the depression in other rotary positions of theclosing element are disposed so as to be mutually offset in thecircumferential direction.
 14. The valve closure as claimed in claim 4,wherein rolling members which project in the direction of the rotationaxis (D) and are rotatable at least in the circumferential direction tothe rotation axis (D) are disposed in the annular bearing face.
 15. Thevalve closure as claimed in claim 1, wherein all closing arms toward thevalve seat have a curved sealing face, wherein the sealing face,proceeding from the center (Z), in a first sub-portion in the radialdirection runs in a planar manner, and subsequently in the radialdirection toward the periphery runs so as to be curved along a secondsub-portion.
 16. A method for operating a valve closure of a pistoncompressor valve, wherein the valve closure comprises a valve seathaving a plurality of passage openings, a closing element and a shafthaving a rotation axis (D), wherein the closing element for opening andclosing the passage openings is rotated about the rotation axis (D),wherein the closing element is formed in one piece and is fixedlyconnected to the shaft, that the shaft is seated in the valve seat so asto be rotatable about the rotation axis (D) and so as to be displaceablein the direction of the rotation axis (D), that the closing element byvirtue of a fluid pressure prevalent on the piston compressor valve islifted in a self-acting manner in the direction of the rotation axis(D), and that the closing element after lifting from the valve seat isrotated in a manner actively driven by the shaft and the passageopenings are thus completely opened.
 17. The method as claimed in claim16, wherein in a first method step the closing element for opening thevalve closure is lifted from the valve seat, and in that in a secondmethod step the closing element after lifting is rotated to an openposition.
 18. The method as claimed in claim 16, wherein the position ofthe closing element in relation to the valve seat is measured, and inthat the closing element is rotated about the rotation axis (D) onlyupon having been lifted from the valve seat.
 19. The method as claimedin claim 17, wherein the closing element is rotated to the open positionwithin a duration of 2 milliseconds to 10 milliseconds upon having beenlifted from the valve seat.